In automotive production, the trend to use electronic modules to deal with the various tasks of safety as well as environmental protection is unabated. Since, despite the use of bus systems, the number of electrical cables and plug connections is steadily increasing, one attempts to control the situation with miniaturization and to keep the number of cable set variants within limits. However, since the handling of miniaturized plug-in systems is problematic and even a moderate failure rate is not tolerable, the development must continue. A factor for reducing failure rates is the prevention of corrosion on electrical contacts. This includes the sealing of plug housings. Plug housings are already sealed very elaborate to protect against external environmental influences such as moisture. A method known in the art is to provide individual electrical cables with a single seal. Another possibility is to use a mat seal for sealing a plurality of cables simultaneously. These methods are well established, but show weaknesses when the plug-in systems become very small. With the plug-in systems becoming smaller, also the tolerances that are to be maintained are smaller.
Further problems arise when the plug-in systems are to be automatically fitted with contact parts. In the case of mat-sealed plug-in systems, the contact elements need to be pushed through the through-openings during assembly. Here, faulty plug-ins have fatal consequences and generate high rework costs. The mat seals used in some plug-in systems tend to deform. This happens when the plug is fitted and the cable diameters expand the sealing openings. Here, a hole offset can occur which makes the subsequent assembly problematic. The contact element is deflected during insertion through the now displaced opening of the sealing and cannot be inserted into the rear contact chamber. Furthermore, the mat seal may be damaged. A further problem for the mat seals and other sealing elements are the sharp edges of the contact elements and the plug housings. These can generally not be avoided during manufacture. They may cut into the sealing material and damage the seal. Last but not least, the problem of vibration plays a growing role in vehicle technology. New engine generations cause vibrations in all conceivable frequency ranges. Under certain conditions, these vibrations can drastically reduce the lifetime of vehicle components.
FIG. 1 shows a sealed plug according to the prior art in sectional view. The sealing element 10 is not yet inserted into the housing opening 31 of the plug housing 30. The sealing element 10 is formed in one piece. It has a profile 19 at the outer circumference and in the through-openings 12.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.